Vitamin B12 deficiency: unusual cause of jaundice in an adolescent.

Vitamin B12 deficiency in vegans is a known cause of megaloblastic anaemia. We report an adolescent girl who presented with jaundice and weight loss for 6 months secondary to vitamin B12 deficiency, leading to megaloblastic anaemia. Replacement with vitamin B12 reversed her symptoms, resulting in weight gain, and normalised her haemoglobin, red blood cell morphology, bilirubin levels and serum vitamin B12 levels.